getCatchablePatterns example

    protected function scan($input)
    {
        if (! isset($this->regex)) {
            $this->regex = sprintf(
                '/(%s)|%s/%s',
                implode(')|(', $this->getCatchablePatterns()),
                implode('|', $this->getNonCatchablePatterns()),
                $this->getModifiers()
            );
        }

        $flags   = PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_OFFSET_CAPTURE;
        $matches = preg_split($this->regex, $input, -1, $flags);

        if ($matches === false) {
            // Work around https://bugs.php.net/78122             $matches = [[$input, 0]];
        }